Several recent developments have highlighted the unintended — though often foreseeable — consequences the president’s policies are having on his own supporters.

In many cases, he’s following through on campaign promises — like cutting the flow of immigrants, renegotiating trade deals and rolling back regulations put in place by Barack Obama. But in the deeply interconnected global economy, the devil is always in the details and the implementation of some policies may do more to hurt than help the people who put their faith in him to fix their problems.

Here are four examples:

-- Small business owners who voted for Trump might be forced to shut down because the president is making it harder for them to hire guest workers. Here’s a story that appeared over the weekend in the Herald Leader of Lexington, Ky.:

“Eddie Devine voted for [Trump] because he thought he would be good for American business. Now, he says, the Trump administration’s restrictions on seasonal foreign labor may put him out of business. ‘I feel like I’ve been tricked by the devil,’ said Devine, owner of … Devine Creations Landscaping. ‘I feel so stupid.’ Devine says it has been years since he could find enough dependable, drug-free American workers for his $12-an-hour jobs mowing and tending landscapes for cemeteries, shopping centers and apartment complexes across Central Kentucky. So for years he has hired 20 seasonal workers, mostly from Guatemala, through the U.S. Labor Department’s H2-B ‘guest worker’ program. Importing these workers for a few months cost him an additional $18,000 in fees and expenses beyond their wages, which must be the same as he pays American workers. But that’s the only way he could serve his customers.

“Restrictions on guest-worker visas, which began during President Barack Obama’s second term as immigration became a hot issue for conservatives, have gotten worse under Trump. And it’s even more of a problem now that the unemployment rate is the lowest it has been in years. Devine says he lost a $100,000 account because he didn’t have enough men to do the job. …

“He isn’t alone. Cuts in H-2B visas are hurting small businesses across the country that can’t find Americans willing to do hard, manual labor: Maryland crab processors, Texas shrimp fishermen, and Kentucky landscapers and construction companies. Devine said he believed Trump’s America-first promises. But cutting off a good supply of seasonal foreign labor when Americans won’t take those jobs is only hurting American business owners and the U.S. workers they employ, he said. These workers aren’t immigrants, and there is no path to U.S. citizenship. When their seasonal work is done, they return home. That’s why Devine thinks the Trump administration’s stifling of guest-worker programs has more to do with racism than economics. ‘I think there’s a war on brown people,’ he said.

“But what makes him most angry is that Trump’s properties in Florida and New York have used 144 H-2B workers since 2016. ‘I want to know why it’s OK for him to get his workers, but supporters like me don’t get theirs,’ Devine said.”

-- General Motors is cutting its second shift at the Lordstown Assembly plant outside of Youngtown, Ohio, next month. The move could cost 1,500 jobs at the 3,000-employee plant that builds the Chevrolet Cruze. This is in the heart of the Mahoning Valley, long a Democratic stronghold that broke toward Trump in 2016 because of his popularity with the kinds of blue-collar workers who are about to lose their jobs or reluctantly take buyouts.

GM says it’s downsizing because there is “lower customer demand for compact cars.” The plant already downsized last year, moving from three shifts to two, partly because consumers are buying more crossovers, SUVs and trucks at the expense of smaller vehicles.

Rep. Tim Ryan (D-Ohio), who represents the plant, blames reduced demand, and the pending layoffs, on Trump’s decision to scrap fuel efficiency standards — which the auto companies did not want. “While low gas prices paved the way for the decline of compact cars … Trump’s April announcement to weaken fuel economy standards put his thumb on the scale in favor of the larger cars and SUV’s made elsewhere, hurting our community specifically,” the congressman said in a statement last Friday. “The truth is, the fuel economy standards help sell more Chevy Cruzes.”

President Trump speaks at an event in North Charleston, S.C., last year to celebrate the construction of the Boeing 787-10 Dreamliner. (Kevin Lamarque/Reuters)

-- Ironically, gas prices might go up because Trump pulled out of the Iranian nuclear agreement last week. (Iran is the world’s fifth-biggest oil producer.)

-- The president’s decision to pull out of the Iran deal, and reimpose sanctions, will cost Boeing contracts worth as much as $20 billion to replenish Iran’s aging fleet of commercial planes. The Chicago-based aerospace giant downplayed the impact last week, noting that there’s already a backlog of orders for 737 aircraft so production won’t slow. But $20 billion in planes represents quite a lot of manufacturing work.

Those jobs will now go to other countries — specifically Russia. “Russian aircraft makers, who can skirt the U.S. sanctions, are already working on deals,” the Puget Sound Business Journal reports. “A Russian aircraft maker is exploring plans to make a modified version of its Sukhoi Superjet 100 regional airliner so Iranian airlines can buy the jet.”

-- The trade war with China is increasing uncertainty for farmers and may still lead to punishing retaliatory tariffs.

China buys 60 percent of all U.S. soybean exports, and growers of the crop could be pressed hard if the administration cannot cut a deal with Beijing. Soybean-producing counties went for Trump by a margin of more than 12 percent in 2016.

Dave Walton, who voted for Trump and tends soybeans, corn and livestock in eastern Iowa, is not sure his farm could take the added stress. “If this turns into a longer-term thing, we’re going to see friends and neighbors go out of business,” he told Caitlin Dewey last month. “If this stretches into years, we ourselves won’t be able to sustain it.”

Walton’s 800-acre farm, in his family for 118 years, has already been struggling to stay above water with falling crop prices, and tariffs could make profitability difficult. “Right now, soybean growers in Iowa and across the nation are encouraging the administration to engage positively with China,” he said. And if that doesn’t happen, he added: “Iowa leads the nation in many things. The presidential election is one of them.”

Trump said that his voters are patriots who are happy to sacrifice for their Dear Leader. It sounds like some of them might not be so excited to be thrown over the cliff for the greater good.